The ground seemed to shift abruptly, and then shift back. Across and down the valley, five miles away, a portion of the stony wall detached itself and slid downward in seeming slow motion. Two more great trees made ripping sounds. One crashed. There was an enormous darkness above one part of the sky. Its under side glowed from fires as of hell, in the crater beneath it. There were sparkings above the mountaintop. Very oddly indeed, the sky overhead was peacefully blue. But at the horizon a sheet of fire rolled down mile-long slopes. It seemed to move with infinite deliberation, but to move visibly at such a distance it must have been traveling like an express-train. It must have been unthinkably hot, glaring-white molten stone, thin as water, pouring downward in a flood of fire. There was no longer a sensation of the ground trembling underfoot. Now the noticeable sensation was when the ground was still. Temblors were practically continuous. There were distinct sharp impacts, as of violent blows nearby. Babs stared, fascinated. She glanced up at Cochrane. His skin was white. There were beads of sweat on his forehead. "We're safe here, aren't we?" she asked, scared. "I think so. But I'm not going to take you through falling trees while this is going on! There's another tree down! I'm worrying about the ship! If it topples--." She looked at the nose of the space-ship, gleaming silver metal, rising from the trees about the landing-spot it had burned clear. A third of its length was visible. "If it topples," said Cochrane, "we'll never be able to take off. It has to point up to lift." Babs looked from the ship to him, and back again. Then her eyes went fearfully to the remote mountain. Rumblings came from it now. They were not loud. They were hardly more than dull growlings, at the lower limit of audible pitch. They were like faint and distant thunder. There were flashings like lightning in the cloud which now enveloped the mountain's top. Cochrane made an indescribable small sound. He stared at the ship. As explosion-waves passed over the ground, a faint, unanimous movement of the treetops became visible. It seemed to Cochrane that the space-ship wavered as if about to fall from its upright position. It was not designed to stand such violence as a fall would imply. Its hull would be dented or rent. It was at least possible that its fuel-store would detonate. But even if its fall were checked by still-standing trees about it, it could never take off again. The eight humans of its company could never juggle it back to a vertical position. Rocket-thrust would merely push it in the direction its nose pointed. Toppled, its rocket-thrust would merely shove it blindly over stones and trees and to destruction.